In this paper we study properties of a homomorphism ρ from the universal enveloping algebra U = U (gl(n + 1)) to a tensor product of an algebra D ′ (n) of differential operators and U (gl(n)). We find a formula for the image of the Capelli determinant of gl(n + 1) under ρ, and, in particular, of the images under ρ of the Gelfand generators of the center Z(gl(n + 1)) of U . This formula is proven by relating ρ to the corresponding Harish-Chandra isomorphisms, and, alternatively, by using a purely computational approach. Furthermore, we define a homomorphism from D ′ (n) ⊗ U (gl(n)) to an algebra containing U as a subalgebra, so that σ(ρ(u)) − u ∈ G 1 U , for all u ∈ U , where G 1 = n i=0 E ii .